1 files changed, 147 insertions, 0 deletions
diff --git a/tracecmd/trace-stream.c b/tracecmd/trace-stream.c
new file mode 100644
index 00000000..ee310f3d
--- /dev/null
+++ b/tracecmd/trace-stream.c
@@ -0,0 +1,147 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2014 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
+ *
+ */
+#include <stdio.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+
+#include <sys/time.h>
+#include <sys/types.h>
+
+#include "trace-local.h"
+
+/*
+ * Stream runs for a single machine. We are going to cheat
+ * and use the trace-output and trace-input code to create
+ * our pevent. First just create a trace.dat file and then read
+ * it to create the pevent and handle.
+ */
+struct tracecmd_input *
+trace_stream_init(struct buffer_instance *instance, int cpu, int fd, int cpus,
+		  struct hook_list *hooks,
+		  tracecmd_handle_init_func handle_init, int global)
+{
+	struct tracecmd_input *trace_input;
+	struct tracecmd_output *trace_output;
+	static FILE *fp = NULL;
+	static int tfd;
+	static int ofd;
+	long flags;
+
+	if (instance->handle) {
+		trace_input = instance->handle;
+		goto make_pipe;
+	}
+
+	if (!fp) {
+		fp = tmpfile();
+		if (!fp)
+			return NULL;
+		tfd = fileno(fp);
+
+		ofd = dup(tfd);
+		trace_output = tracecmd_output_create_fd(ofd);
+		if (!trace_output) {
+			fclose(fp);
+			return NULL;
+		}
+		tracecmd_output_write_headers(trace_output, NULL);
+		tracecmd_output_free(trace_output);
+	}
+
+	lseek(ofd, 0, SEEK_SET);
+
+	trace_input = tracecmd_alloc_fd(ofd, 0);
+	if (!trace_input) {
+		close(ofd);
+		goto fail;
+	}
+
+	if (tracecmd_read_headers(trace_input, TRACECMD_FILE_PRINTK) < 0)
+		goto fail_free_input;
+
+	if (handle_init)
+		handle_init(trace_input, hooks, global);
+
+ make_pipe:
+	/* Do not block on this pipe */
+	flags = fcntl(fd, F_GETFL);
+	fcntl(fd, F_SETFL, flags | O_NONBLOCK);
+
+	if (tracecmd_make_pipe(trace_input, cpu, fd, cpus) < 0)
+		goto fail_free_input;
+
+	instance->handle = trace_input;
+
+	return trace_input;
+
+ fail_free_input:
+	tracecmd_close(trace_input);
+ fail:
+	fclose(fp);
+
+	return NULL;
+}
+
+int trace_stream_read(struct pid_record_data *pids, int nr_pids, struct timeval *tv)
+{
+	struct tep_record *record;
+	struct pid_record_data *pid;
+	struct pid_record_data *last_pid;
+	fd_set rfds;
+	int top_rfd = 0;
+	int nr_fd;
+	int ret;
+	int i;
+
+	last_pid = NULL;
+
+ again:
+	for (i = 0; i < nr_pids; i++) {
+		pid = &pids[i];
+
+		if (!pid->record)
+			pid->record = tracecmd_read_data(pid->instance->handle, pid->cpu);
+		record = pid->record;
+		if (!record && errno == EINVAL)
+			/* pipe has closed */
+			pid->closed = 1;
+
+		if (record &&
+		    (!last_pid || record->ts < last_pid->record->ts))
+			last_pid = pid;
+	}
+	if (last_pid) {
+		trace_show_data(last_pid->instance->handle, last_pid->record);
+		tracecmd_free_record(last_pid->record);
+		last_pid->record = NULL;
+		return 1;
+	}
+
+	nr_fd = 0;
+	FD_ZERO(&rfds);
+
+	for (i = 0; i < nr_pids; i++) {
+		/* Do not process closed pipes */
+		if (pids[i].closed)
+			continue;
+		nr_fd++;
+		if (pids[i].brass[0] > top_rfd)
+			top_rfd = pids[i].brass[0];
+
+		FD_SET(pids[i].brass[0], &rfds);
+	}
+
+	if (!nr_fd)
+		return 0;
+
+	ret = select(top_rfd + 1, &rfds, NULL, NULL, tv);
+
+	if (ret > 0)
+		goto again;
+
+	return ret;
+}